Antimitotic activity and reversal of breast cancer resistance protein-mediated drug resistance by stilbenoids from Bletilla striata

New stilbene metabolites isolated from the tuber of Bletilla striata and their biological assessment

A phytochemical investigation of the tuber of Bletilla striata afforded eight stilbene derivatives, including a new bibenzyl (1) and two new phenanthrene (2 and 3). The structures of these compounds were elucidated using a combination of spectroscopic analyses. Further, the anti-inflammatory activity of all the compounds was evaluated to assess their capability to inhibit nitric oxide (NO) production by RAW 264.7 macrophages. The bioactive screening revealed that compounds 4 and 7 exhibited moderate inhibitory effects against NO production with the IC50 values 38.7 and 16.7 μM, respectively.

Study on Process Optimization and Antioxidant Activity of Polysaccharide from Bletilla striata Extracted via Deep Eutectic Solvents

Taking the extraction yield of Bletilla striata polysaccharide (BSP) as the index and taking the type of deep eutectic solvents (DESs), extraction time, extraction temperature, DES water content, and solid-liquid ratio as the investigation factors, single-factor and Box-Behnken response surface tests were carried out to optimize the extraction process of BSP. Thus, the antioxidant activity of BSP on DPPH radicals, ABTS radicals and ferric reducing antioxidant power were determined. The results showed that the most suitable deep eutectic solvent was DES-2, namely choline chloride-urea. The optimal extraction conditions for BSP were an extraction time of 47 min, extraction temperature of 78 °C, water content of 35%, and solid-liquid ratio of 1:25. Under this optimized condition, the extraction yield of BSP was able to reach (558.90 ± 8.83) mg/g, and recycling studies indicated the good cycle stability of the DES. Antioxidant results showed that BSP had superior antioxidant activity and had a dose-response relationship with drug concentration. Compared with Bletilla striata polysaccharide obtained via conventional hot water extraction (BSP-W), the extraction yield of BSP obtained through this method (BSP-2) increased by 36.77%, the scavenging activity of DPPH radicals increased by 24.99%, the scavenging activity of ABTS radicals increased by 41.16%, and the ferric reducing antioxidant power increased by 49.19%. Therefore, DESs as new green reagents and BSP extracted with DESs not only had a high yield but also had strong antioxidant activity.

Metabolite Chemical Composition of the Bletilla striata (Thunb.) Reichb. f. Endophyte Penicillium oxalicum

Penicillium oxalicum strain can be isolated from the Bletilla striata (Thunb.) Reichb. f. tubers. Its solid-state fermentation products are concentrated by percolation extraction. Separation and purification have been conducted to the ethyl acetate extracts by preparative HPLC. Based on the use of spectrometry, we have determined 17 known compounds, 12,13-dihydroxy-fumitremorgin C (1), pseurotin A (2), tyrosol (3), cyclo-(L-Pro-L-Val) (4), cis-4-hydroxy-8-O-methylmellein (5), uracil (6), cyclo-(L-Pro-L-Ala) (7), 1,2,3,4-tetrahydro-4-hydroxy-4-quinolin carboxylic acid (8), cyclo-(Gly-L-Pro) (9), 2'-deoxyuridine (10), 1-(β-D-ribofuranosyl)thymine (11), cyclo-(L-Val-Gly) (12), 2'-deoxythymidine (13), cyclo-(Gly-D-Phe) (14), cyclo-L-(4-hydroxyprolinyl)-D-leucine (15), cyclo-(L)-4-hydroxy-Pro-(L)-Phe (16), uridine (17). Here, we report compounds 1-3, 5, 7-8, 11-12, 14-17 are first found and isolated from this endophyte.

Dihydrophenanthrene Dimers: Why and Where It Is Possible to Isolate Their Precursors

An interesting class of compounds of natural origin is dihydrophenanthrene dimers, which are characterized by a series of remarkable biological properties. Considering the hypothesis that each dimer is obtained through a biosynthetic mechanism that involves the coupling of the corresponding radicals of the single dihydrophenanthrene unit, we identified 29 dihydrophenanthrenes. Of these dihydrophenanthrenes, 11 were new compounds that could be isolated from 10 different plant species; 11 had already been identified, but not yet isolated in the 17 different plant species from which the corresponding dimers had been isolated; and 7 were known and had been isolated in the same plant sources of the corresponding dimers. A targeted analysis of several natural extracts from specific plant sources would allow the identification of known or new molecules with potential and/or specific biological activities and, in a final analysis, would confirm the relative biosynthetic mechanism.

Comparative study on the extraction efficiency, characterization, and bioactivities of Bletilla striata polysaccharides using response surface methodology (RSM) and genetic algorithm-artificial neural network (GA-ANN)

This research established the optimal conditions for alkali-assisted extraction (AAE) of bioactive polysaccharides from Bletilla striata integrated with response surface methodology (RSM) and the genetic algorithm-artificial neural networks (GA-ANN). In comparison with RSM, the ANN model showed a relatively higher determination coefficient in the global output values (RSM: ANN = 0.9270: 0.9742) performing more satisfactorily in the validation. Under the optimum conditions (52 °C; 167 min, and 0.01 mol/L NaOH), the extraction yields, IC₅₀ of ABTS, and FRAP value were 29.53 ± 0.97 %, 3.41 mg/mL, and 39.11 μmol Fe²⁺/g, respectively. The results indicated that BSPs-A was mainly composed of glucose and mannose with small amounts of arabinose, galactose, and galacturonic acid, while possessed a molecular weight of about 305.94 kDa (Mw). The structural characterization of BSPs-A was initially characterized by FT-IR, SEM, and Congo red tests, which indicated that BSPs-A possessed a triple helix conformation of typical Bletilla striata polysaccharides. In addition, BSPs-A exhibited excellent antioxidant activity, which was further confirmed by a series of in vitro antioxidant activity assays including DPPH, ABTS, FRAP, and ORAC. After incubation in the BSA-glucose system for 15 days, BSPs-A showed inhibition of the advanced glycation end products (AGEs) formation for the first time.

Xylochemical Synthesis and Biological Evaluation of the Orchidaceous Natural Products Isoarundinin I, Bleochrin F, Blestanol K, and Pleionol

The first total syntheses of the orchid-derived natural products isoarundinin I (1), (±)-bleochrin F ((±)-2), (±)-blestanol K ((±)-3), and (±)-pleionol ((±)-4) from renewable starting materials are reported, along with the evaluation of their biological activities. The total syntheses were based on regioselective aromatic bromination reactions in combination with a key acid-promoted regioselective intramolecular cyclization. The biological results suggest that isoarundinin I (1), (±)-blestanol K ((±)-3), and (±)-pleionol ((±)-4) have the potential to inhibit the growth of both sensitive and multidrug-resistant cancer cells.

Comprehensive evaluation of Bletilla striata and its substitutes by combining phenotypic characteristic, chemical composition, and anti-melanogenic activity

Bletilla striata is a precious traditional Chinese medical herb with a wide range of applications in pharmacological and cosmetic fields. Because of the shortage of resources, Bletilla ochracea and Bletilla formosanare are also used as the substitutes. To distinguish the differences and homologies, the typical morphologic and microscopic characteristics of them were compared, and a UPLC fingerprint analysis coupled with chemometric methods were developed for characterization and quality evaluation of Bletillae Rhizoma. Gastrodin, protocatechuic acid, gymnoside V, blestrianol A, coelonin, gymnosides Ⅸ and batatasin II were identified as the potential chemical markers for comprehensive quality evaluation by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The anti-melanogenic activities of the three species were also compared for the first time in vivo using the zebrafish model, the results suggested that B. striata and its two substitutes had obvious anti-melanogenic activities, and they were not-toxic at depigmenting doses. Molecular docking studies revealed batatasin III, blestrianol A, coelonin, and gastrodin were possible multitarget compounds associated with melanogenesis suppression, which are important for their potential future medical application.

Discovery and identification of potential anti-melanogenic active constituents of Bletilla striata by zebrafish model and molecular docking

BACKGROUND

Bletilla striata is the main medicine of many skin whitening classic formulas in traditional Chinese medicine (TCM) and is widely used in cosmetic industry recently. However, its active ingredients are still unclear and its fibrous roots are not used effectively. The aim of the present study is to discover and identify its potential anti-melanogenic active constituents by zebrafish model and molecular docking.

METHODS

The antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis-(3-ethylbenthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity and ferric reducing antioxidant power (FRAP) assay. The anti-melanogenic activity was assessed by tyrosinase inhibitory activity in vitro and melanin inhibitory in zebrafish. The chemical profiles were performed by ultra-high-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Meanwhile, the potential anti-melanogenic active constituents were temporary identified by molecular docking.

RESULTS

The 95% ethanol extract of B. striata fibrous roots (EFB) possessed the strongest DPPH, ABTS, FRAP and tyrosinase inhibitory activities, with IC50 5.94 mg/L, 11.69 mg/L, 6.92 mmol FeSO4/g, and 58.92 mg/L, respectively. In addition, EFB and 95% ethanol extract of B. striata tuber (ETB) significantly reduced the melanin synthesis of zebrafish embryos in a dose-dependent manner. 39 chemical compositions, including 24 stilbenoids were tentatively identified from EFB and ETB. Molecular docking indicated that there were 83 (including 60 stilbenoids) and 85 (including 70 stilbenoids) compounds exhibited stronger binding affinities toward tyrosinase and adenylate cyclase.

CONCLUSION

The present findings supported the rationale for the use of EFB and ETB as natural skin-whitening agents in pharmaceutical and cosmetic industries.

The medicinal uses of the genus Bletilla in traditional Chinese medicine: A phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Different orchids are important in traditional medicine, and species belonging to the genus Bletilla are important. Bletilla species have been used for thousands of years in Traditional Chinese Medicine (TCM) for the treatment of several health disorders, such as gastrointestinal disorders, peptic ulcer, lung disorders, and traumatic bleeding etc. AIM OF THIS REVIEW: This review aims to provide a systematic overview and objective analysis of Bletilla species and to find the probable relationship between their traditional use, chemical constituents, and pharmacological activities, while assessing their therapeutic potential in treatment of different human diseases.

MATERIALS AND METHODS

Relevant literatures on Bletilla species have been collected using the keywords "Bletilla", "phytochemistry", and "pharmacology" in scientific databases, such as "PubMed", "Scifinder", "The Plant List", "Elsevier", "China Knowledge Resource Integrated databases (CNKI)", "Google Scholar", "Baidu Scholar", and other literature sources, etc. RESULTS: This review indicates the isolation and identification of over 261 compounds from this genus, till December 2020. These chemical isolates belong to the stilbenes (bibenzyls and phenanthrenes), flavonoids, triterpenoids, steroids, simple phenolics, and glucosyloxybenzyl 2-isobutylmalates classes of compounds. These compounds have been reported to be characteristically distributed in Bletilla striata (Thunb.) Rchb. f. (BS), Bletilla ochracea Schltr. (BO), and Bletilla formosana (Hayata) Schltr. (BF). The crude extracts and pure compounds derived from the three Bletilla species have reportedly exhibited a wide spectrum of in vitro and in vivo pharmacological effects, such as hemostatic, anti-inflammatory, anti-tumor, and anti-microbial activities. As a Traditional Chinese Medicine (TCM), Bletilla species or preparations containing Bletilla species have been used for the treatment of epistaxis, gastrointestinal bleeding, cough and hemoptysis, gastric and duodenal ulcer, and traumatic injuries. Thus, Bletilla species have proven potential both in traditional uses and scientific studies.

CONCLUSIONS

Pharmacological studies have validated the use of Bletilla species in the traditional medicine, especially hemorrhagic diseases. Polysaccharides and stilbenes are the major bioactive chemical constituents of Bletilla genus according to the literatures. However, the mechanism of action of these molecules is yet to be studied. In addition, a detailed comparative analysis of the phytochemistry and biological activities of the three Bletilla species (BS, BO and BF) is highly recommended for understanding their ethnopharmacological uses and applications in clinics. Clinical toxicity tests on BS have been found to be negative, but it can't be used with Aconitum carmichaeli in traditional uses. Furthermore, not many reports are present in the literature regarding the conservation of Bletilla species.

Phytochemistry and pharmacological activities of Arundina graminifolia (D.Don) Hochr. And other common Orchidaceae medicinal plants

ETHNOPHARMACOLOGICAL RELEVANCE

Arundina graminifolia (Orchidaceae) has been widely used for heat clearance and detoxification, anti-inflammatory diuretic, and anti-microbes for two thousand years in national minorities, especially among the Dai people. It was known as "Zhuyelan" (Chinese: ), "Wenshanghai" (Chinese: ) and "Baiyangjie" (Chinese: ) in the Dai nationality, and mainly used as antidote, which is characterized by "relieving the poison before getting sick and treating illness". Therefore, it has been typically applied in the treatment of food poisoning, snake bites, rheumatism, stomachache and traumatic injuries. It is also used to treat bronchitis, tuberculosis and pneumonia in the Bulang and the Wa ethnic people.

AIM OF THIS REVIEW

This review aims to provide up-to-date information about the botanical characterization, traditional uses, phytochemistry, and pharmacology of A. graminifolia, and the related importantly medicinal plants (e.g. Bletilla striata, Cremastra appendiculata, and Dendrobium officinale) of the same Orchidaceae family. Our work aims to further promote scientific cognition, basic research and in-depth discovery of potential drug candidates for Minority Medicine of our nation.

MATERIALS AND METHODS

Relevant information was obtained via piles of resources including classic books about Chinese herbal medicine, and worldwide accepted scientific databases including Web of Science, Pubmed, Google Scholar, SciFinder, Elsevier, Springer, NCBI, ACS Publications, CNKI and Wanfang data.

RESULTS

Phytochemical investigations have been intensively performed for these two decades, over 134 compounds, mainly include stilbenoids, phenanthrenes, quinones, ketones, phenolic acids, and glycosides, have been isolated and identified from A. graminifolia. The literature surveys exhibited that the ethnomedicinal uses of A. graminifolia, such as detoxification, anti-inflammation and the ability to cure trauma and pain associated with infections, are correlated with its modern pharmacological activities, including antibacterial, anti-oxidation, anti-lipid peroxidation. Stilbenoids and phenanthrenes have been regarded as the main active substances, among which stilbenoids with open ring style have superior antitumor activity. Furthermore, phytochemical investigations, biological activities, as well as the main molecular mechanism involved the coexisted stilbenoids and phenanthrenes from other most common used medicinal plants of the same Orchidaceae family were presented, compared and discussed together.

CONCLUSIONS

This review presents the current research findings of A. graminifolia and three other related medicinal plants of the same family. Some of the traditional uses of A. graminifolia have been assessed by pharmacological studies. Despite A. graminifolia is used as an antidote and anti-aging dote, a few unsolved problems including the molecular mechanism underlying biological activities, pharmacokinetics, and in vivo detoxification tests still need to be settled extensively. Therefore, it is necessary to conduct a comprehensive survey and collect investigation information on A. graminifolia.

Bletinib ameliorates neutrophilic inflammation and lung injury by inhibiting Src family kinase phosphorylation and activity

BACKGROUND AND PURPOSE

Neutrophil overactivation is crucial in the pathogenesis of acute lung injury (ALI). Bletinib (3,3'-dihydroxy-2',6'-bis(p-hydroxybenzyl)-5-methoxybibenzyl), a natural bibenzyl, extracted from the Bletilla plant, exhibits anti-inflammatory, antibacterial, and antimitotic effects. In this study, we evaluated the therapeutic effects of bletinib in human neutrophilic inflammation and LPS-mediated ALI in mice.

EXPERIMENTAL APPROACH

In human neutrophils activated with the formyl peptide (fMLP), we assessed integrin expression, superoxide anion production, degranulation, neutrophil extracellular trap (NET) formation, and adhesion through flow cytometry, spectrophotometry, and immunofluorescence microscopy. Immunoblotting was used to measure phosphorylation of Src family kinases (SFKs) and downstream proteins. Finally, a LPS-induced ALI model in male BALB/c mice was used to investigate the potential therapeutic effects of bletinib treatment.

KEY RESULTS

In activated human neutrophils, bletinib reduced degranulation, respiratory burst, NET formation, adhesion, migration, and integrin expression; suppressed the enzymic activity of SFKs, including Src, Lyn, Fgr, and Hck; and inhibited the phosphorylation of SFKs as well as Vav and Bruton's tyrosine kinase (Btk). In mice with ALI, the pulmonary sections demonstrated considerable amelioration of prominent inflammatory changes, such as haemorrhage, pulmonary oedema, and neutrophil infiltration, after bletinib treatment.

CONCLUSION AND IMPLICATIONS

Bletinib regulates neutrophilic inflammation by inhibiting the SFK-Btk-Vav pathway. Bletinib ameliorates LPS-induced ALI in mice. Further biochemical optimisation of bletinib may be a promising strategy for the development of novel therapeutic agents for inflammatory diseases.

Anti-Inflammatory Effect Fraction of Bletilla striata and Its Protective Effect on LPS-Induced Acute Lung Injury

Bletilla striata is a well-known traditional Chinese herb with anti-inflammatory properties that is widely used in the treatment of lung conditions such as silicosis, tuberculosis, and pneumogastric hemorrhage. However, little information on the anti-inflammatory ingredients and their activities is available. In this study, an effect fraction of Bletilla striata (EFBS) was enriched, and its anti-inflammatory activities and underlying mechanisms were investigated. EFBS was enriched by polyamide column chromatography and characterized by HPLC; an LPS-induced acute lung injury model was used to evaluate the anti-inflammatory activities of EFBS. Meanwhile, the main anti-inflammation-contributing ingredients and possible molecular mechanism of anti-inflammatory activity in EFBS were verified by component-knockout method combined with LPS-induced RAW264.7 cell model. The EFBS mainly consisted of coelonin (15.88%), batatasin III (32.49%), 3′-O-methylbatatasin III (6.96%), and 3-hydroxy-5-methoxy bibenzyl (2.51%). Pretreatment with the EFBS (20 mg/kg and 60 mg/kg) for five days prior to the administration of LPS resulted in decreases in wet-to-dry lung weight ratio, neutrophil number, MPO activity, total protein concentration, NO level, and MDA level, as well as IL-1β, IL-6, MCP-1, and TNF-α concentrations in the bronchoalveolar lavage fluid. Western blot analysis demonstrated the increased expressions of iNOS, COX-2, and NF-κB p65 in the LPS treatment group, all of which were ameliorated by EFBS pretreatment. Histological examination confirmed the protective effect of the EFBS. Additionally, component-knockout assay confirmed that these four quantitative components contributed significantly to the anti-inflammatory effect of EFBS. Coelonin, batatasin III, 3′-O-methylbatatasin III and 3-hydroxy-5-methoxy bibenzyl were the main anti-inflammatory components of EFBS and could regulate the expression of downstream inflammatory cytokines by inhibiting p65 nuclear translocation. These findings uncover, in part, the molecular basis underlying the anti-inflammatory activity of Bletilla striata.

Phenanthrene, 9,10-dihydrophenanthrene and bibenzyl enantiomers from Bletilla striata with their antineuroinflammatory and cytotoxic activities

Thirteen undescribed phenanthrene and bibenzyl derivatives, named blestanols A-M, including one pair of biphenanthrene enantiomers, two bis 9,10-dihydrophenanthrene ethers, five pairs of 9,10-dihydrophenanthrene/bibenzyl atropisomers, one racemic 9,10-dihydrophenanthrene/bibenzyl dimer, one 9,10-dihydrophenanthrenebibenzyl ether, two pairs of bibenzyl derivatives, and one stilbene, together with 12 known analogues were isolated from the tubers of Bletilla striata. The structures were elucidated via spectroscopic data analysis. 15 compounds were purified to yield enantiomers (a, b) via chiral-phase HPLC, and their configurations were determined by optical rotation values and the comparison of the experimental and calculated electronic circular dichroism (ECD) curves. Blestanols K-L possessed a cycloheptene moiety, which is rarely observed in bibenzyl derivatives. A putative biosynthetic pathway for the identified components is deduced. Among these compounds, 14 compounds showed inhibition of NO production, with IC₅₀ values ranging from 5.0 to 19.0 μM. Eight compounds displayed selective cytotoxic activities against HCT-116, HepG2, BGC-823, A549 or U251 cancer cell lines, with IC₅₀ values ranging from 1.4 to 8.3 μM. In addition, their structure-activity relationships are discussed briefly.

Proteomic profiling uncovered the cytosolic superoxide dismutase BsSOD1 associated with plant defence in the herbal orchid Bletilla striata

The herbal orchid Bletilla striata (Thunb.) Rchb.f. has a long cultivation history and has been widely used in medicines and cosmetics. The fungal infection leaf blight (LB) seriously threatens B. striata cultivation. Here, we systemically collected wild B. striata accessions and isolated the accessions with strong resistance against LB. We carried out proteomic profiling analysis of LB-resistant and LB-susceptible accessions, and identified a large number of differentially expressed proteins with significant gene ontology enrichment for 'oxidoreductase activity.' Of the proteins identified in the reactive oxygen species signalling pathway, the protein abundance of the Cu-Zn superoxide dismutase BsSOD1 and its gene expression level were higher in LB-resistant accessions than in LB-susceptible lines. Transient expression of the dismutase fused with yellow fluorescent protein determined that its subcellular localisation is in the cytoplasm. Our study provides new insights into the molecular markers associated with fungal infection in B. striata.

Chemical Constituents, Pharmacologic Properties, and Clinical Applications of Bletilla striata

Bletilla striata is a plant from the Orchidaceae family that has been employed as a traditional Chinese medicine (TCM) for thousands of years in China. Here, we briefly review the published studies of the last 30 years that were related to chemical constituents, pharmacologic activities, and clinical applications of B. striata. Approximately 158 compounds have been extracted from B. striata tubers with clarified molecular structures that were classified as glucosides, bibenzyls, phenanthrenes, quinones, biphenanthrenes, dihydrophenanthrenes, anthocyanins, steroids, triterpenoids, and phenolic acids. These chemicals support the pharmacological properties of hemostasis and wound healing, and also exhibit anti-oxidation, anti-cancer, anti-viral, and anti-bacterial activities. Additionally, various clinical trials conducted on B. striata have demonstrated its marked activities as an embolizing and mucosa-protective agent, and its application for use in novel biomaterials, quality control, and toxicology. It also has been widely used as a constituent of many preparations in TCM formulations, but because there are insufficient studies on its clinical properties, its efficacy and safety cannot be established from a scientific point of view. We hope that this review will provide reference for further research and development of this unique plant.

Antibacterial bibenzyl derivatives from the tubers of Bletilla striata

Ten previously undescribed bibenzyl derivatives (bletistrins A-J), including 5 that have hydroxyl-substituted chiral centres on the aliphatic bibenzyl bridge, along with twelve known bibenzyl derivatives, were isolated from the rhizomes of Bletilla striata. The structures of bletistrins A-J were primarily elucidated on the basis of their 1D and 2D NMR spectroscopic data. The absolute configurations of bletistrins A, D, F, H and I were determined by electronic circular dichroism (ECD) spectroscopic analysis and optical rotation value. Most of the isolated compounds were evaluated for their antibacterial activities against 3 g-positive bacterial strains and 1 g-negative bacterial strain. Bletistrins F, G, and J, bulbocol, shanciguol and shancigusin B showed inhibitory activities, with MICs of (3-28 μg/mL) against S. aureus ATCC 6538.

Bletilla striata: a review of seedling propagation and cultivation modes

In recent years, the domestic and international market demand for Bletilla striata has increased rapidly because of its wide use in medical, pharmaceutical, chemical, health, cosmetology, and other fields. The increased demand and a shortage of wild herbal resources have led to the development of large-scale introduction and cultivation programs. Using our research results and the relevant literature, this paper characterizes the original B. striata plant, as well as seedling propagation techniques and its main cultivation modes, and discusses some problems in the B. striata production process. This work will provide a reference for industry development and the promotion of B. striata.

Quality evaluation and traceability of Bletilla striata by fluorescence fingerprint coupled with multiway chemometrics analysis

BACKGROUND

Traditional methods of evaluating herbs were mainly based on chromatographic techniques. They usually included tedious sample preparation procedures, taking tens of minutes to hours, and consume solvents as well as standards for external calibration. In this paper, the feasibility of employing a fluorescence fingerprint coupled with multi-way chemometrics analysis for quality evaluation and traceability of Bletilla striata were investigated.

RESULTS

Relative concentrations of four markers presented in B. striata were determined by using a four-component self-weighted alternating trilinear decomposition (SWATLD) model. These markers could be applied to accurate classification and quality control of B. striata samples from different regions. Furthermore, multiway principal component analysis, multilinear partial least squares discriminant analysis (PLS-DA), unfolded PLS-DA, and SWATLD-PLS-DA models were applied to classify the B. striata samples according to their geographic origins. Consistent results were obtained showing that B. striata samples could be successfully grouped based on their geographical origins and quality.

CONCLUSION

Our results revealed that the method developed can be used for quality evaluation and traceability of B. striata. Compared with the chromatographic methods, the method employed in this study was more convenient, simpler, and more sensitive. © 2018 Society of Chemical Industry.

Phenolic compounds from Bletilla striata

Two new malic acid derivatives, namely eucomic acid 1-methyl ester (2) and 6'''-acetylmilitaline (7), together with ten known compounds (1, 3-6, 8-12), were isolated from the dry tubers of Bletilla striata (Thunb.) Reichb. F., a perennial traditional Chinese medicinal herb, which was used for the treatment of pneumonophthisis, pneumonorrhagia, tuberculosis, and hemorrhage of the stomach or lung. Their structures were elucidated by spectroscopic analyses, including 1D-, 2D-NMR, and HR-ESI-MS.

Mechanisms of drug resistance in colon cancer and its therapeutic strategies

Drug resistance develops in nearly all patients with colon cancer, leading to a decrease in the therapeutic efficacies of anticancer agents. This review provides an up-to-date summary on over-expression of ATP-binding cassette (ABC) transporters and evasion of apoptosis, two representatives of transport-based and non-transport-based mechanisms of drug resistance, as well as their therapeutic strategies. Different ABC transporters were found to be up-regulated in colon cancer, which can facilitate the efflux of anticancer drugs out of cancer cells and decrease their therapeutic effects. Inhibition of ABC transporters by suppressing their protein expressions or co-administration of modulators has been proven as an effective approach to sensitize drug-resistant cancer cells to anticancer drugs in vitro. On the other hand, evasion of apoptosis observed in drug-resistant cancers also results in drug resistance to anticancer agents, especially to apoptosis inducers. Restoration of apoptotic signals by BH3 mimetics or epidermal growth factor receptor inhibitors and inhibition of cancer cell growth by alternative cell death pathways, such as autophagy, are effective means to treat such resistant cancer types. Given that the drug resistance mechanisms are different among colon cancer patients and may change even in a single patient at different stages, personalized and specific combination therapy is proposed to be more effective and safer for the reversal of drug resistance in clinics.

Three new 1-(p-hydroxybenzyl)phenanthrenes from Bletilla striata

Three new benzylphenanthrenes, named 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2-ol (1), 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2,8-diol (2), and 1-(p-hydroxybenzyl)-4,7-dimethoxyphenanthrene-2,6-diol (3), along with a known analog were isolated from tubers of Bletilla striata. The structures of these new compounds were established by means of HR-ESI-MS, 1D, and 2D NMR.

Bletilla striata: Medicinal uses, phytochemistry and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Bletilla striata (Thunb.) Reichb. f. (Orchidaceae), also known as Hyacinth Orchid and Baiji (Simplified Chinese: ), not only has been widely used for the treatment of hematemesis, hemoptysis, and traumatic bleeding due to the efficacy of arresting bleeding with astringent action, but also has been applied topically to overcome ulcers, sores, swellings, and chapped skin due to the efficacy of dispersing swelling and promoting tissue regeneration. Additional medical applications include the treatment of tuberculosis, malignant ulcers, hemorrhoids, anthrax, eye diseases, and silicosis.

AIM OF THIS REVIEW

This review aims to provide up-to-date information on the botanical characterization, medicinal uses, chemical constituents, pharmacological activities, and toxicity of B. striata. In addition, this paper also focuses on the possible exploitation of this plant for the treatment of different diseases, and uncovers opportunities for future research.

MATERIALS AND METHODS

The relevant information on B. striata was gathered from worldwide accepted scientific databases via an electronic search (Google Scholar, Web of Science, ScienceDirect, ACS Publications, PubMed, Wiley Online Library, SciFinder, CNKI). Information was also obtained from The Plant List, Chinese pharmacopoeia, Chinese herbal classics books, PhD and MSc dissertations, etc.

RESULTS

A comprehensive analysis of the literature obtained through the above-mentioned sources confirmed that the ethnomedical usages of B. striata have been recorded in Mongolia, Korea, Japan, and China. Phytochemical investigations revealed that the major chemical constituents of B. striata are polysaccharides, bibenzyls, phenanthrenes, triterpenoids and its saponins, steroids and its saponins, which also have been proven to be the main bioactive substances capable of exhibiting numerous pharmacological activities including wound healing, antiulcer, hemostasis, cytotoxicity, antimicrobial, anti-inflammation, anti-oxidation, immunomodulation, anti-fibrosis, antiaging, anti-allergy, and anti-itch.

CONCLUSIONS

Preliminary investigations on pharmacological properties of B. striata have shown that B. striata is an outstanding astringent hemostatic medicinal, B. striata polysaccharides (BSP) as the major bioactive components not only capable of promoting wound healing, but also show good performance as a kind of promising natural biomaterial. More importantly, BSP are also reported to be excellent embolic material. However, further investigations need to be carried out to fully clarify its efficacy of dispersing swelling and promoting tissue regeneration. Moreover, this plant also needs a lot more investigations to clarify the pathways of absorption, distribution, metabolism and excretion, and to evaluate its long-term in vivo chronic toxicity before proceeding to the development of pharmaceutical formulation.

ABCG2/BCRP: Specific and Nonspecific Modulators

Multidrug resistance (MDR) in cancer cells is the development of resistance to a variety of structurally and functionally nonrelated anticancer drugs. This phenomenon has become a major obstacle to cancer chemotherapy seriously affecting the clinical outcome. MDR is associated with increased drug efflux from cells mediated by an energy-dependent mechanism involving the ATP-binding cassette (ABC) transporters, mainly P-glycoprotein (ABCB1), the MDR-associated protein-1 (ABCC1), and the breast cancer resistance protein (ABCG2). The first two transporters have been widely studied already and reviews summarized the results. The ABCG2 protein has been a subject of intense study since its discovery as its overexpression has been detected in resistant cell lines in numerous types of human cancers. To date, a long list of modulators of ABCG2 exists and continues to increase. However, little is known about the clinical consequences of ABCG2 modulation. This makes the design of novel, potent, and nontoxic inhibitors of this efflux protein a major challenge to reverse MDR and thereby increase the success of chemotherapy. The aim of the present review is to describe and highlight specific and nonspecific modulators of ABCG2 reported to date based on the selectivity of the compounds, as many of them are effective against one or more ABC transport proteins.

Chemical Constituents of the Rhizomes of Bletilla formosana and Their Potential Anti-inflammatory Activity

Nine new phenanthrenes (1-9) and a new benzyl glycoside (10) together with 45 known compounds were isolated from the rhizomes of Bletilla formosana. The structures of 1-10 were elucidated primarily on the basis of their 1D and 2D NMR spectroscopic data. Most of the isolated compounds were evaluated for their anti-inflammatory activities. The results showed that IC50 values for the inhibition of superoxide anion generation and elastase release ranged from 0.2 to 6.5 μM and 0.3 to 5.7 μM, respectively. Structure-activity relationships of the isolated compounds were also investigated. The inhibitory potencies were determined as phenanthrenes > bibenzyls > biphenanthrenes.

Mechanisms of drug resistance in colon cancer and its therapeutic strategies

Drug resistance develops in nearly all patients with colon cancer, leading to a decrease in the therapeutic efficacies of anticancer agents. This review provides an up-to-date summary on over-expression of ATP-binding cassette (ABC) transporters and evasion of apoptosis, two representatives of transport-based and non-transport-based mechanisms of drug resistance, as well as their therapeutic strategies. Different ABC transporters were found to be up-regulated in colon cancer, which can facilitate the efflux of anticancer drugs out of cancer cells and decrease their therapeutic effects. Inhibition of ABC transporters by suppressing their protein expressions or co-administration of modulators has been proven as an effective approach to sensitize drug-resistant cancer cells to anticancer drugs in vitro. On the other hand, evasion of apoptosis observed in drug-resistant cancers also results in drug resistance to anticancer agents, especially to apoptosis inducers. Restoration of apoptotic signals by BH3 mimetics or epidermal growth factor receptor inhibitors and inhibition of cancer cell growth by alternative cell death pathways, such as autophagy, are effective means to treat such resistant cancer types. Given that the drug resistance mechanisms are different among colon cancer patients and may change even in a single patient at different stages, personalized and specific combination therapy is proposed to be more effective and safer for the reversal of drug resistance in clinics.

Synthesis, self-assembly, and in vitro toxicity of fatty acids-modified Bletilla striata polysaccharide

Hydrophobic modification of Bletilla striata polysaccharide (BSP) was performed by grafting fatty acids to BSP backbone and then characterized on their physicochemical properties. All neutral derivatives were able to self-assemble into spherical particles within the size range of 250-400 nm, their size and critical micelle concentration decreased with increasing hydrophobicity and substitution degree of the fatty acids. Also, the BSP-stearic acid conjugates showed a preferable performance on hemolysis test and cytotoxicity analysis on HepG2 cells, which suggested their potential application as a drug delivery vector.

The therapeutic effect of Bletilla striata extracts on LPS-induced acute lung injury by regulation of inflammation and oxidation

Identification of active ingredients, and their structures, from Bletilla striata and investigation of the antioxidative and anti-inflammatory responses in vitro and in vivo.

The bacterial communities associated with fecal types and body weight of rex rabbits

Rex rabbit is an important small herbivore for fur and meat production. However, little is known about the gut microbiota in rex rabbit, especially regarding their relationship with different fecal types and growth of the hosts. We characterized the microbiota of both hard and soft feces from rex rabbits with high and low body weight by using the Illumina MiSeq platform targeting the V4 region of the 16S rDNA. High weight rex rabbits possess distinctive microbiota in hard feces, but not in soft feces, from the low weight group. We detected the overrepresentation of several genera such as YS2/Cyanobacteria, and Bacteroidales and underrepresentation of genera such as Anaeroplasma spp. and Clostridiaceae in high weight hard feces. Between fecal types, several bacterial taxa such as Ruminococcaceae, and Akkermansia spp. were enriched in soft feces. PICRUSt analysis revealed that metabolic pathways such as “stilbenoid, diarylheptanoid, gingerol biosynthesis” were enriched in high weight rabbits, and pathways related to “xenobiotics biodegradation” and “various types of N-glycan biosynthesis” were overrepresented in rabbit soft feces. Our study provides foundation to generate hypothesis aiming to test the roles that different bacterial taxa play in the growth and caecotrophy of rex rabbits.

ABC transporters in multidrug resistance and pharmacokinetics, and strategies for drug development

Multidrug resistance (MDR) is a serious problem that hampers the success of cancer pharmacotherapy. A common mechanism is the overexpression of ATP-binding cassette (ABC) efflux transporters in cancer cells such as P-glycoprotein (P-gp/ABCB1), multidrug resistance-associated protein 1 (MRP1/ABCC1) and breast cancer resistance protein (BCRP/ABCG2) that limit the exposure to anticancer drugs. One way to overcome MDR is to develop ABC efflux transporter inhibitors to sensitize cancer cells to chemotherapeutic drugs. The complete clinical trials thus far have showen that those tested chemosensitizers only add limited or no benefits to cancer patients. Some MDR modulators are merely toxic, and others induce unwanted drug-drug interactions. Actually, many ABC transporters are also expressed abundantly in the gastrointestinal tract, liver, kidney, brain and other normal tissues, and they largely determine drug absorption, distribution and excretion, and affect the overall pharmacokinetic properties of drugs in humans. In addition, ABC transporters such as P-gp, MRP1 and BCRP co-expressed in tumors show a broad and overlapped specificity for substrates and MDR modulators. Thus reliable preclinical assays and models are required for the assessment of transporter-mediated flux and potential effects on pharmacokinetics in drug development. In this review, we provide an overview of the role of ABC efflux transporters in MDR and pharmacokinetics. Preclinical assays for the assessment of drug transport and development of MDR modulators are also discussed.

Antioxidant, antityrosinase and antitumor activity comparison: the potential utilization of fibrous root part of Bletilla striata (Thunb.) Reichb.f

This study was carried out to evaluate the utilization probability of the fibrous root part (FRP) of Bletilla striata, which was usually discarded and harvesting pseudobulb part (PSP). The chemical composition, total phenolic content, DPPH radical scavenging activity, Ferric-reducing antioxidant power and tyrosinase inhibition activity were compared between FRP and PSP. Antioxidant and pro-oxidant effect as well as antitumor effect of the extract of FRP and PSP were analyzed by in vitro cell system as well. Thin layer chromatography and high performance liquid chromatography analysis indicated that the chemical compositions in the two parts were similar, but the content in FRP was much higher than PSP. Meanwhile, the FRP extracts showed higher phenolic content, stronger DPPH scavenging activity, Ferric-reducing antioxidant capacity and tyrosinase inhibition activity. Sub-fraction analysis revealed that the distribution characteristic of phenolic components and other active constituents in FRP and PSP were consistent, and mainly deposited in chloroform and acetoacetate fractions. Especially, the chloroform sub-fraction (sch) of FRP showed extraordinary DPPH scavenging activity and tyrosinase inhibition activity, with IC₅₀ 0.848 mg/L and 4.3 mg/L, respectively. Besides, tyrosinase inhibition activity was even stronger than the positive compound arbutin (31.8 mg/L). Moreover, In vitro cell system analysis confirmed that FRP extract exerts comparable activity with PSP, especially, the sub-fraction sch of FRP showed better antioxidant activity at low dosage and stronger per-oxidant activity at high dosage, and both sch of FRP and PSP can dose-dependent induce HepG2 cells apoptosis, which implied tumor therapeutic effect. Considering that an additional 0.3 kg FRP would be obtained when producing 1.0 kg PSP, our work demonstrated that FRP is very potential to be used together with PSP.

Discovering natural product modulators to overcome multidrug resistance in cancer chemotherapy

Multidrug resistance caused by the overexpression of ABC drug transporters is a major obstacle in clinical cancer chemotherapy. For several years, it appeared that direct inhibition of ABC transporters would be the cheapest and most efficient way to combat this problem. Unfortunately, progress in finding a potent, selective inhibitor to modulate ABC transporters and restore drug sensitivity in multidrug-resistant cancer cells has been slow and challenging. Candidate drugs should ideally be selective, potent and relatively non-toxic. Many researchers in recent years have turned their attention to utilizing natural products as the building blocks for the development of the next generation of inhibitors, especially after the disappointing results obtained from inhibitors of the first three generations at the clinical trial stage. The first step is to discover natural substances (distinct from the first three generation inhibitors) that are potent, selective and relatively non-toxic in order to be used clinically. Here, we present a brief overview of the prospect of using natural products to modulate the function of ABC drug transporters clinically and their impact on human physiology and pharmacology.

Therapeutic orchids: traditional uses and recent advances--an overview

Orchids have been used as a source of medicine for millennia to treat different diseases and ailments including tuberculosis, paralysis, stomach disorders, chest pain, arthritis, syphilis, jaundice, cholera, acidity, eczema, tumour, piles, boils, inflammations, menstrual disorder, spermatorrhea, leucoderma, diahorrhea, muscular pain, blood dysentery, hepatitis, dyspepsia, bone fractures, rheumatism, asthma, malaria, earache, sexually transmitted diseases, wounds and sores. Besides, many orchidaceous preparations are used as emetic, purgative, aphrodisiac, vermifuge, bronchodilator, sex stimulator, contraceptive, cooling agent and remedies in scorpion sting and snake bite. Some of the preparations are supposed to have miraculous curative properties but rare scientific demonstration available which is a primary requirement for clinical implementations. Incredible diversity, high alkaloids and glycosides content, research on orchids is full of potential. Meanwhile, some novel compounds and drugs, both in phytochemical and pharmacological point of view have been reported from orchids. Linking of the indigenous knowledge to the modern research activities will help to discover new drugs much more effective than contemporary synthetic medicines. The present study reviews the traditional therapeutic uses of orchids with its recent advances in pharmacological investigations that would be a useful reference for plant drug researches, especially in orchids.

Reversing agents for ATP-binding cassette drug transporters

The multidrug resistance (MDR) phenotype exhibited by cancer cells is believed to be the major barriers to successful chemotherapy in cancer patients. The major form of MDR phenotype is contributed by a group of ATP-binding cassette (ABC) drug transporters which include P-glycoprotein, multidrug resistance-associated protein 1, and breast cancer resistance protein. There has been intense search for compounds which can act to reverse MDR phenotype in cultured cells, in animal models, and ultimately in patients. The ongoing search for MDR modulators, compounds that act directly on the ABC transporter proteins to block their activity, has led to three generations of drugs. Some of the third-generation MDR modulators have demonstrated encouraging results compared to earlier generation MDR modulators in clinical trials. These modulators are less toxic and they do not affect the pharmacokinetics of anti-cancer drugs. Significant numbers of natural products have also been identified for their effectiveness in reversing MDR in a manner similar to the MDR modulators. Other MDR reversing strategies that have been studied quite extensively are also reviewed and discussed in this chapter. These include strategies aimed at destroying mRNAs for ABC drug transporters, approaches in inhibiting transcription of ABC transporter genes, and blocking of ABC transporter activity using antibodies. This review summarizes the development of reversing agents for ABC drug transporters up to the end of 2008, and provides an optimistic view of what we have achieved and where we could go from here.

BCRP expression does not result in resistance to STX140 in vivo, despite the increased expression of BCRP in A2780 cells in vitro after long-term STX140 exposure

The anti-proliferative and anti-angiogenic properties of the endogenous oestrogen metabolite, 2-methoxyoestradiol (2-MeOE2), are enhanced in a series of sulphamoylated derivatives of 2-MeOE2. To investigate possible mechanisms of resistance to these compounds, a cell line, A2780.140, eightfold less sensitive to the 3,17-O,O-bis-sulphamoylated derivative, STX140, was derived from the A2780 ovarian cancer cell line by dose escalation. Other cell lines tested did not develop STX140 resistance. RT-PCR and immunoblot analysis demonstrated that breast cancer resistance protein (BCRP) expression is dramatically increased in A2780.140 cells. The cells are cross-resistant to the most structurally similar bis-sulphamates, and to BCRP substrates, mitoxantrone and doxorubicin; but they remain sensitive to taxol, an MDR1 substrate, and to all other sulphamates tested. Sensitivity can be restored using a BCRP inhibitor, and this pattern of resistance is also seen in a BCRP-expressing MCF-7-derived cell line, MCF-7.MR. In mice bearing wild-type (wt) and BCRP-expressing tumours on either flank, both STX140 and mitoxantrone inhibited the growth of the MCF-7wt xenografts, but only STX140 inhibited growth of the MCF-7.MR tumours. In conclusion, STX140, a promising orally bioavailable anti-cancer agent in pre-clinical development, is highly efficacious in BCRP-expressing xenografts. This is despite an increase in BCRP expression in A2780 cells in vitro after chronic dosing with STX140.

Antimitotic activity of two macrocyclic bis(bibenzyls), isoplagiochins A and B from the Liverwort Plagiochila fruticosa

Two bis(bibenzyls), isoplagiochins A (1) and B (2) have been isolated by the guidance of inhibitory effect of tubulin polymerization from the liverwort Plagiochila fruticosa (Plagiochilaceae). Isoplagiochins A and B inhibited the polymerization of tubulin at IC(50) 50 and 25muM, respectively. Furthermore structure-activity relationship based on their conformations was discussed. The presence of two aromatic rings which can be connected through two atoms bridge spacer of double bond may serve to maintain the backbone conformation.